Sean Doolittle and Ryan Madson are on the move as the A's have traded the veteran relievers to the Nationals.
Oakland will receive RHP Blake Treinen, INF Sheldon Neuse and LHP Jesus Luzardo from Washington.
The deal ends Doolittle's six-year run with the A's, which comes on the heels of the end of Stephen Vogt's tenure in Oakland.
Madson is in the second year of a three-year, $22 million deal.
In 23 games this season, Doolittle has a 3.38 ERA and three saves, while Madson posted a 2.08 ERA in 40 appearances.
Treinen returns to the team that drafted him in the seventh round of the 2011 MLB Draft. The A's traded Treinen in 2013 as part of a three-team deal involving the Nationals and Mariners. The 29-year-old has struggled this season to the tune of a 5.73 ERA in 37 games.
Neuse, the Nationals' No. 6 prospect according to MLBPipeline.com, is hitting .291 with nine homers and 51 RBI for Low-A Hagerstown.
Luzardo is a 19-year-old left-handed pitcher just getting his start in pro ball. Drafted in the third round of the 2016 MLB Draft, Luzardo has pitched in just three games for the Rookie-ball Gulf Coast League Nationals. Despite his lack of experience, MLBPipeline.com had Luzardo ranked as Washington's No. 10 prospect.